 /*******************************************************************************
  * Copyright (c) 2000, 2005 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  * IBM Corporation - initial API and implementation
  *******************************************************************************/

 package org.eclipse.ui.commands;

 /**
  * <p>
  * A category is a grouping of commands by functional area. For example, in the
  * Eclipse workbench, "Text Editing" is a category containing various commands
  * related to text editing. A category's primary functionality is to control the
  * display of commands to the user. When appropriate, commands displayed to the
  * user (e.g., keys preference page) will be grouped by category.
  * </p>
  * <p>
  * An instance of <code>ICategory</code> is a handle representing a category
  * as defined by the extension point <code>org.eclipse.ui.commands</code>.
  * The identifier of the handle is identifier of the category being represented.
  * </p>
  * <p>
  * An instance of <code>ICategory</code> can be obtained from an instance of
  * <code>ICommandManager</code> for any identifier, whether or not a category
  * with that identifier defined in the plugin registry.
  * </p>
  * <p>
  * The handle-based nature of this API allows it to work well with runtime
  * plugin activation and deactivation, which causes dynamic changes to the
  * plugin registry, and therefore, potentially, dynamic changes to the set of
  * category definitions.
  * </p>
  * <p>
  * This interface is not intended to be extended or implemented by clients.
  * </p>
  *
  * @since 3.0
  * @see ICategoryListener
  * @see ICommandManager
  * @see org.eclipse.core.commands.Category
  * @deprecated Please use the "org.eclipse.core.commands" plug-in instead.
  */
 public interface ICategory extends Comparable {

     /**
      * Registers an instance of <code>ICategoryListener</code> to listen for
      * changes to attributes of this instance.
      *
      * @param categoryListener
      * the instance of <code>ICategoryListener</code> to register.
      * Must not be <code>null</code>. If an attempt is made to
      * register an instance of <code>ICategoryListener</code>
      * which is already registered with this instance, no operation
      * is performed.
      */
     void addCategoryListener(ICategoryListener categoryListener);

     /**
      * <p>
      * Returns the description of the category represented by this handle,
      * suitable for display to the user.
      * </p>
      * <p>
      * Notification is sent to all registered listeners if this attribute
      * changes.
      * </p>
      *
      * @return the description of the category represented by this handle.
      * Guaranteed not to be <code>null</code>.
      * @throws NotDefinedException
      * if the category represented by this handle is not defined.
      */
     String getDescription() throws NotDefinedException;

     /**
      * Returns the identifier of this handle.
      *
      * @return the identifier of this handle. Guaranteed not to be <code>null</code>.
      */
     String getId();

     /**
      * <p>
      * Returns the name of the category represented by this handle, suitable
      * for display to the user.
      * </p>
      * <p>
      * Notification is sent to all registered listeners if this attribute
      * changes.
      * </p>
      *
      * @return the name of the category represented by this handle. Guaranteed
      * not to be <code>null</code>.
      * @throws NotDefinedException
      * if the category represented by this handle is not defined.
      */
     String getName() throws NotDefinedException;

     /**
      * <p>
      * Returns whether or not the category represented by this handle is
      * defined.
      * </p>
      * <p>
      * Notification is sent to all registered listeners if this attribute
      * changes.
      * </p>
      *
      * @return <code>true</code>, iff the category represented by this
      * handle is defined.
      */
     boolean isDefined();

     /**
      * Unregisters an instance of <code>ICategoryListener</code> listening
      * for changes to attributes of this instance.
      *
      * @param categoryListener
      * the instance of <code>ICategoryListener</code> to
      * unregister. Must not be <code>null</code>. If an attempt
      * is made to unregister an instance of <code>ICategoryListener</code>
      * which is not already registered with this instance, no
      * operation is performed.
      */
     void removeCategoryListener(ICategoryListener categoryListener);
 }

